1. Field of the Invention
This invention relates to the cutting of vegetation, and more particularly, it relates to the cutting of vegetation using a flexible non-metallic line extending from a rotating head into a cutting plane.
2. Description of the Prior Art
Various types of devices have been proposed for many years to facilitate the removal of vegetation by mowing, trimming, edging and like cutting operations. In general, these devices have employed a metal blade to effect vegetation removal. Devices of this nature employ powerful prime movers such as electric and gasoline motors. As a result, serious and terrible injury could be inflicted upon the user where unintended contact occurred with rotating metal blades.
In about 1960, there was developed in Europe a trimmer or edger unit employing a flexible polymeric line extending from a rotating head for cutting vegetation. This unit did not work properly because of several defects in structure and operating parameters. In the United States of America, practical cutting devices, using flexible non-metallic lines carried upon a rotating head were developed. These devices are shown in U.S. Pat. Nos. 3,708,967, 3,828,068, 3,859,776, 4,035,912, 4,052,789 and 4,054,992. These patented devices have met outstanding success in that these American developments are probably the safest power operated tools yet invented for vegetation cutting, edging and trimming operations. In particular the gasoline powered devices employing the invention of these patents have found outstanding use for such heavy vegetation removal as in the right aways for roads and power lines, cemetery cleaning and like vegetation cutting operations wherein the growth can become excessive. In particular, the gasoline powered devices are employed to good effect in both commercial and private vegetation cutting operations. These devices generally carry topside a gasoline motor at one end of a drive tube which extended downwardly to a lower rotating head which carries one or more Nylon.RTM. polymer cutting lines. Rotation of the cutting head extends the cutting line radially outwardly into a cutting plane wherein the vegetation is cut. One or more accessory handles placed adjacent the motor facilitate the operator in controlling vegetation cutting. At the lower end of the drive tube, a housing is mounted and provides a bearing upon which the rotating cutting head is journaled. The housing carries (1) a circular bearing skirt which extends axially towards the cutting head, (2) a superimposed shoulder, and (3) surfaces upon which a guard or shield is secured by bolts.
Although the cutting lines carried upon the cutting head may comprise one or more Nylon.RTM. polymeric members having diameters between 0.065 and 0.100 inches, heavy vegetative cutting operations with time cause the lines to be frayed, broken, and otherwise shortened. When desired to replenish the cutting line from the conventional cutting head, cutting operation of the unit had to be stopped. Then, additional line was extended manually from the head. For example, the cutting line might be carried upon a spool internally of the cutting head. The spool was released for rotation and additional line length pulled from the head into the cutting plane. Then, the spool was again secured against rotation in the head. In the more powerful vegetating cutting apparatus powered by gasoline motors, the time expended in stopping the unit and extending additional line is a waste and reduces the cutting efficiency of these units. It is desirable that the operator continue cutting operations with the ability to extend cutting line from the rotating head in desired lengths and under his complete control.
The present invention is an apparatus for cutting vegetation, in the nature of the patented devices, but uses a simple assembly to provide operator controlled cutting line extensions. The assembly is readily combined with the various power driven vegetating cutting apparatus and without any substantially rebuilding or altering of their original structures, The present invention provides a mechanical line feeding mechanism so that the operator may extend the cutting line in deserete incremental lengths from the cutting head as he desires during cutting operations. Other features of the present invention will be apparent from the following description.